About This Document
This document describes the DDSU666-H Smart Power Sensor, including its functions, electrical properties, and structure. Figures provided are for reference only.
Intended Audience
This document is intended for:
- Sales engineers
- Technical support engineers
- Maintenance engineers
Symbol Conventions
| Symbol | Description |
|---|---|
| DANGER | Indicates a hazard with a high level of risk which, if not avoided, will result in death or serious injury. |
| WARNING | Indicates a hazard with a medium level of risk which, if not avoided, could result in death or serious injury. |
| CAUTION | Indicates a hazard with a low level of risk which, if not avoided, could result in minor or moderate injury. |
| NOTICE | Indicates a potentially hazardous situation which, if not avoided, could result in equipment damage, data loss, performance deterioration, or unanticipated results. NOTICE is used to address practices not related to personal injury. |
| NOTE | Supplements the important information in the main text. NOTE is used to address information not related to personal injury, equipment damage, and environment deterioration. |
Change History
Changes between document issues are cumulative. The latest document issue contains all updates made in previous issues.
- Issue 03 (2021-10-10): Updated 2.3 Application Scenarios, 2.7 Installing the DDSU666-H Cable.
- Issue 02 (2021-03-01): Updated 2.6 Installing the DDSU666-H, 2.7 Installing the DDSU666-H Cable.
- Issue 01 (2018-03-01): First official release.
1 Safety Precautions
General Safety
- Follow the precautions and special safety instructions provided by Huawei when operating this product. Personnel who plan to install or maintain Huawei devices must receive thorough training, understand all necessary safety precautions, and be able to correctly perform all operations. Huawei will not be liable for any consequences caused by the violation of general safety regulations and device usage safety standards.
- Before performing operations, read through this manual and follow all precautions to prevent accidents. The "DANGER", "WARNING", "CAUTION", and "NOTICE" statements in this document are supplements to the safety instructions.
- Operation personnel should comply with local laws and regulations. The safety instructions in this document are supplements to local laws and regulations.
- Do not operate the product or handle cables during thunderstorms.
- Before operating the product, remove any conductors such as jewelry or watches.
- Use insulated tools during operations.
- Bolts should be tightened with a torque wrench and marked using red or blue color. Installation personnel should mark tightened bolts in blue. Quality inspection personnel should confirm if the bolts are tightened and then mark them in red. If screws or bolts used to secure the device are not tightened to the required torque, the device may fall from the mounting bracket.
- Follow specified procedures during installation and maintenance. Do not attempt to alter the device or deviate from the recommended installation procedures without prior consent from the manufacturer.
- Install the product in strict accordance with the quick guide.
Disclaimer
Huawei shall not be liable for any consequence caused by any of the following events:
- Transportation damage
- Storage conditions not meeting requirements
- Incorrect installation or use
- Installation or use by unqualified personnel
- Failure to obey operation instructions and safety precautions
- Operation in extreme environments not covered in this document
- Device operation beyond specified ranges
- Unauthorized modifications to the product or software code
- Device damage due to force majeure (lightning, fire, storm)
- Expired warranty or non-extended warranty service
- Installation or use in environments not specified in related international standards
Personnel Requirements
Only certified electricians are allowed to install, connect cables for, maintain, troubleshoot, and replace the DDSU666-H.
- Operation personnel should receive professional training.
- Operation personnel should read through this document and follow all precautions.
- Operation personnel should be familiar with the safety specifications about the electrical system.
- Operation personnel should understand the composition and working principles of the grid-tied PV power system and local regulations.
- Operation personnel must wear proper personal protective equipment (PPE).
Protect Labels
- Do not scrawl or damage any warning labels on the DDSU666-H as they contain important information about safe operation.
- Do not scrawl or damage the nameplate on the back of the DDSU666-H as it contains important product information.
Installation
- Ensure that the DDSU666-H is not connected to a power supply or powered on before finishing installation.
- To allow proper heat dissipation and installation, maintain appropriate clearances between the DDSU666-H and other objects.
Electrical Connections
DANGER: Before connecting cables, ensure that the DDSU666-H is not damaged in any way. Otherwise, electric shocks or fire may occur.
- Ensure that all electrical connections comply with local electrical standards.
- Ensure that the cables used in a grid-tied PV system are properly connected and insulated and meet all specification requirements.
Operation
DANGER: High voltage may cause an electric shock, which results in serious injury, death, or serious property damage from the DDSU666-H in operation. Strictly comply with the safety precautions in this document and associated documents when operating the DDSU666-H.
- Do not touch an energized DDSU666-H as it has a high temperature.
- Follow local laws and regulations when operating the device.
Maintenance and Replacement
DANGER: High voltage may cause an electric shock, which results in serious injury, death, or serious property damage from the DDSU666-H in operation. Therefore, before maintenance, power off the DDSU666-H and strictly comply with the safety precautions in this document and associated documents to operate the DDSU666-H.
- Maintain the DDSU666-H with sufficient knowledge of this document and proper tools and testing devices.
- Temporary warning signs or fences must be placed to prevent unauthorized people from entering the site.
- The DDSU666-H can be powered on only after all faults are rectified. Failing to do so may escalate faults or damage the device.
- During maintenance, observe ESD precautions and wear ESD gloves.
2 Overview
2.1 Product Overview
The DDSU666-H Smart Power Sensor is designed for distributed photovoltaic systems. It is a smart power sensor that combines measurement and communication, primarily used for measuring electrical quantities such as voltage, current, power, frequency, power factor, and active energy in electrical circuits. It can network with external devices via RS485 communication interface. With a standard DIN35mm DIN rail mounting and structural module design, it is characterized by small volume, easy installation, and networking.
The performance index of the meter conforms to the following technical standards:
- EN 61326-1:2013
- IEC 61326-1:2012
- EN 61326-2-1:2013
- IEC 61326-2-1:2012
- EN 61010-1:2010
- IEC 61010-1:2010
- EN 61010-2-1:2010
- IEC 61010-2-1:2010
Diagram showing the front and side views of the DDSU666-H Smart Power Sensor with labels for model, specifications (100A/40mA, 50/60Hz), CE mark, and terminal connections (5, 6, 24, 25).
2.2 Working Principles
Conceptual Diagram
The Sensor converts voltage and current signals into signals identifiable by the MCU via the sampling circuit. The MCU calculates and converts these signals into energy, power, power factor, and other electrical quantities. This information is transferred to users through communication and saved in the storage circuit. Refer to the conceptual diagram in Figure 2-2.
Block diagram showing Voltage U, Current I, Sampling circuit, MCU, Power circuit, Memory circuit, and Communication circuit.
Functions
- Metering function: Accurately meters positive/reverse active energy and combined active energy, with no data loss after power interruption.
- Measurement function of electrical parameters: Accurately measures electrical parameters including power, voltage, current, frequency, and power factor.
- Display function: Features a field LCD design for displaying electrical parameters and energy data. The energy measurement value has six digits, with a display range from 0 to 999999 kWh.
Illustration of the LCD display showing "Imp. Exp NO. TIME MKVVAh" and numerical values.
- Cyclic display: Characterized with cyclic display function, the shift time of cyclic display is 5 seconds. See the cyclic displayed items in Table 2-1.
| No. | Content | Description |
|---|---|---|
| 1 | Imp. 0001.20 kWh |
Current positive active energy Imp = 1.20 kWh |
| 2 | Exp. 000 1.00 kWh |
Current reverse active energy Exp = 1.00 kWh |
| 3 | P 1.100 kW |
Active power P=1.100 kW |
| 4 | U 220.0 V |
Voltage U=220.0 V |
| 5 | I 5.000 A |
Current I=5.000 A |
| 6 | F 50.00 Hz |
Frequency F=50.00 Hz |
- Button display: The instrument has button display and backlight functions. See button displayed items in Table 2-2.
| No. | Content | Description |
|---|---|---|
| 1 | 0000.20 kWh |
Current combined active energy =0.20 kWh |
| 2 | Imp. 0001.20 kWh |
Current positive active energy Imp = 1.20 kWh |
| 3 | Exp. 0001.00 kWh |
Current reverse active energy Exp = 1.00 kWh |
| 4 | 71.9600 | n.1. data format to be eight bits, none parity bit and one stop bit. 9600: baud rate to be 9600 bps. 4800: baud rate to be 4800 bps. |
| 5 | 011 | Comm.Add=11 |
| 6 | U 220.0 V |
Voltage U=220.0 V |
| 7 | I 5.000 A |
Current I=5.000 A |
| 8 | P 1.100 kW |
Active power P=1.100 kW |
| 9 | Ft 1.000 |
Power factor Ft=1.000 |
| 10 | F 50.00 Hz |
Frequency F=50.00 Hz |
Note: Backlight closes without button operation for sixty seconds.
Note: The combined active energy defaults to positive active energy from the factory.
- Parameter setting function: The sensor can set the communication address and baud rate through buttons. Refer to Figure 2-4 for the setting method. Long press the button for 3 seconds to enter the communication address setting interface.
Diagram illustrating the process of setting communication address and baud rate using buttons, including power on, long press, press once, alternate appearance, and exit conditions.
- Communication function: Equipped with one RS485 communication interface, with baud rate switchable between 4800bps and 9600bps. The default baud rate is 9600bps with check bit and stop bit as n.1. Supports ModBus-RTU protocol.
2.3 Application Scenarios
Scenario 1: Used for power restriction of the power grid with charge and discharge control for energy storage in household inverter schemes. It is a core component for household energy management, adopting RS485 communication for electrical quantity measurement, energy metering, and real-time data query response to the upper host.
NOTE: The smart power sensor is mainly used for power control at the grid-connection point. The measured energy yield and electricity consumption are for reference only and cannot be used for calculating electricity fees. Electricity fee measurement is subject to the meter provided by the grid company.
Diagram illustrating the application scenario of the smart power sensor in a photovoltaic system, showing connections between PV Module, Smart Energy Center, distribution box, Smart Power Sensor, energy storage system, loads, meter of electric utility company, and the Grid.
2.4 Model Naming Conventions
Diagram explaining the model naming convention: D/T/S for electronic type, U for connection mode, and 666 for design number. Specifies D: Single phase AC Energy Meter; T: Three phase four wire AC Energy Meter; S: Three phase three wire AC Energy Meter.
| Model No. | Accuracy grade | Referenced voltage | Current specification | Collector constant | Type |
|---|---|---|---|---|---|
| DDSU666-H | Active Class 1 | 230 V | 100 A/40 mA | 800 imp/kWh | Via transformer |
2.5 Product Structure
Outline dimension: 36mm x 98mm x 66mm; DIN-rail mounting dimension: 35 mm. Refer to Figure 2-7 for outline and installation dimensions.
Diagram showing the dimensions of the DDSU666-H Smart Power Sensor: 36mm (width), 100mm (height), 65mm (depth), with DIN rail mounting dimension of 35mm.
2.6 Installing the DDSU666-H
- Install the smart power sensor on the standard DIN rail of DIN35 mm.
- Install the Smart Power Sensor to the standard DIN rail from the top to the bottom, and then push the instrument to the DIN rail from the bottom to the front part.
Illustrates the steps for installing the smart power sensor onto a DIN rail.
2.7 Installing the DDSU666-H Cable
| Cable | DDSU666-H | Type | Conductor Cross-sectional Area Range | Outer Diameter | Source |
|---|---|---|---|---|---|
| AC power cable | L - 3 | Two-core (L and N) outdoor copper cable | 4-6 mm² | 10-21 mm | Prepared by the customer |
| N - 4 | |||||
| CT cable | I* - 5 | - | - | - | Manufacturer |
| I - 6 | - | - | - | Manufacturer | |
| Comm. cable | RS485A - 24 | Two-core outdoor shielded twisted pair | 0.20-1 mm² | 4-11 mm | Manufacturer |
| RS485B - 25 | Manufacturer |
NOTE:
- The minimum cable diameter must comply with local cable standards.
- Factors affecting cable selection include rated current, cable type, routing mode, ambient temperature, and maximum expected line loss.
- Connect the L, N voltage lines to terminals 3 and 4 of the collector.
- Connect current transformer outlets I*, I to terminals 5 and 6 of the collector.
- Connect RS485A and RS485B to the communication host.
Wiring diagram showing the connection of the DDSU666-H Smart Power Sensor to the SUN2000, power grid, AC switches, and home load, including terminal connections and cable routing.
3 System Maintenance
3.1 Troubleshooting
| Fault phenomenon | Factor analysis | Elimination method |
|---|---|---|
| No display after the instrument being powered on | 1. Incorrect wiring mode; 2. Abnormal voltage supplied for the instrument. |
1. If the wiring mode is incorrect, connect based on the correct wiring mode (see wiring diagram). 2. If the supplied voltage is abnormal, supply the voltage as per the instrument specification. |
| Abnormal RS485 communication | 1. RS485 communication cable is disconnected, short-circuited, or reversely connected. 2. The address, baud rate, data bit, and parity bit of the instrument are not in accordance with the host computer. |
1. If there are problems with the communication cable, reconnect or change the cable. 2. Set the address, baud rate, data bit, and parity bit to be the same as the host computer through buttons (refer to parameter setting). |
| Inaccurate for energy metering | 1. Incorrect wiring; check if the corresponding phase sequence of voltage and current is correct. 2. Check if the high & low end of the current transformer inlet is reversely connected. Observe the power of Pa, Pb, Pc; abnormal if any negative values. |
If the wiring mode is incorrect, connect based on the correct wiring mode (see the wiring diagram). |
NOTE: Contact the installation vendor if all failure analysis procedures are completed and the fault still exists.
4 Technical Specifications
4.1 Environmental Specifications
| Item | Specifications |
|---|---|
| Regulated working temperature range | -25°C to +60°C |
| Limited working temperature range | -35°C to +70°C |
| Relative humidity (Annual average) | ≤ 75% RH |
| Atmospheric pressure | 86-106 kPa |
4.2 Main technical performance and parameter
4.2.1 Electrical parameter
| Specifications | |
|---|---|
| Regulated working voltage range | 176-288 VAC |
| Extended working voltage range | 0.7-1.3 Un |
| Working frequency range | 45-65 Hz |
4.2.2 Percentage error
| Current value | Power factor | The percentage error limitation of various grade instruments | |
|---|---|---|---|
| Direct connect | Via transformer | Class 1 | |
| 0.05 lb ≤ I < 0.1 lb | 0.02 In ≤ I < 0.05 In | 1 | ±1.5 |
| 0.1 lb ≤ I ≤ Imax | 0.05 In ≤ I ≤ Imax | 1 | ±1.0 |
| 0.1 lb ≤ I ≤ 0.2 lb | 0.05 In ≤ I < 0.1 In | 0.5 L | ±1.5 |
| 0.8 C | ±1.5 | ||
| 0.2 lb ≤ I ≤ Imax | 0.1 In ≤ I ≤ Imax | 0.5 L | ±1.0 |
| 0.8 C | ±1.0 | ||
| When users has special requirement | 0.25 L | ±3.5 | |
| 0.2 lb ≤ I ≤ Imax | 0.1 In ≤ I ≤ Imax | 0.5 C | ±2.5 |
4.2.3 Start
| Sensor | Energy meter grade | Power factor |
|---|---|---|
| Direct connect | Class 1 | 1 |
| Via transformer | 0.004 lb | |
| 0.002 lb |
4.2.4 Defluction
When applying voltage while the current circuit has no current, the test output of the instrument shall not produce a superfluous pulse. When testing, the current circuit shall be disconnected and the applied voltage of the voltage circuit shall be 115% of the referenced voltage.
The shortest testing time Δt ≥ (600 x 106) / (k * m * Un * Imax) [min]
For instrument of class 1:
From the formula: k represents energy meter constant (imp/kWh), m represents the testing component quantity, Un represents the referenced voltage (V), Imax represents the large current (A).
4.2.5 Other technical parameters
| Item | Specifications |
|---|---|
| Scale range | 0-999999.99 kWh |
| Communication protocol | Modbus-RTU protocol |
4.3 EMC Specifications
EMC performance of the meter conforms to the following relevant technical standards:
- IEC 61326-1:2012
- IEC 61326-2-1:2012
- EN 61326-1:2013
- EN 61326-2-1:2013
- EN61000-3-2:2005/A2:2009
- EN61000-3-3:2008
4.4 Structure Specifications
4.4.1 Structure specifications
| Item | Specifications |
|---|---|
| Installation mode | Directly stuck the sensor on the DIN rail and finally install it on the power distribution box. 1. When installing, please firstly stuck one side of the card slot and then forcibly stuck it on the DIN rail. 2. When disassembling, please use a screwdriver to forcibly hold the flexible card and then take out the sensor. |
| Dimensions (H x W x D) | 36 mm x 100 mm x 65.5 mm (±0.5 mm) |
| Weight | ≤ 0.3 kg |
5 Acronyms and Abbreviations
This section lists common acronyms and abbreviations used in the document.
- D
- DC: direct current
- E
- EFT: electrical fast transient
- EMI: electromagnetic interference
- EMS: electromagnetic susceptibility
- ESD: electrostatic discharge
- M
- MPPT: maximum power point tracking
- P
- PLC: power line communication
- R
- RE: radiated emission
- RS: radiated susceptibility
